CHAPTER ONE
1.0     INTRODUCTION
Nunu is a spontaneously fermented milk (yoghurt-like) product in Nigeria and other parts of West Africa including Ghana and Burkina Faso. Unlike other African fermented milk products where milk of goats, sheep, and camels is used, Nunu is solely prepared from cow milk. The traditional processing of Nunu involves collecting fresh cow milk into containers and then allowing it to ferment for a day or two days at ambient temperature. Nunu is yoghurt-like in taste (a sharp acid taste) and it can be taken alone or with Fura (Owusu-Kwarteng et al., 2012; Akabanda et al., 2013). Like many other spontaneously fermented foods in  Africa, the production of Nunu is largely home-based and the fermentation is spontaneous. Thus, starter cultures are not available, but old stocks of previous ferments and fermentation containers are used to initiate fermentation in new batches. The dependence on such undefined and diverse microbial consortium during Nunu fermentation may result in product of variable quality and stability.
Currently, there is no information on the use of starter cultures for Nunu fermentation. However, few investigations have been carried out on the microbiology of Ghanaian traditionally fermented milk products (Obodai and Dodd,2006; Akabanda et al., 2010). The predominant microorganisms isolated from this traditionally fermented milk should be developed into starter cultures that could be used to produce fermented milk products of consistent quality and consumer acceptability. Thus, it should be possible to improve the quality and consumer acceptability of Nunu through controlled fermentation using starter culture.
The culture should, however, be well-defined. Such starter cultures must be developed with a clear understanding of the ecology of the microbial species associated with the desirable traditional fermentation process, and their contributions to the products safety and quality are determined. The first stage in designing such starter culture(s) is to characterize and identify the technologically important microorganisms associated with the traditional fermentation of the product and then to test the use of the identified organisms in fermentation trials.
The objective of the present study was therefore to evaluate the technological potential of lactic acid bacteria isolated from spontaneously fermented Nunu in view of their application as starter cultures in Nunu production.